Riveter



Patented Aug. 15, 1939'v t v BIYETER George H. Kessler and William Meier-.Cleveland Ohio, assigner: to The Midland Steel Products Company, Cleveland, Ohio, a .corporation of Ohio Application august 4, 1936, serial No. 94,212

7 Claims.

This invention relates to new and useful improvements in riveters, and more particularly to improvements in hydraulic riveting machines.

An object of the invention is to provide a portable riveter which is strong, durable iand inexpensive of. construction, and which is under the perfect control 'of the operator by manipulating only a single valve in the handle of the riveter.

Another object ofthe invention is to provide l0 a portableriveter which is relatively small in l size and contains intensifying means to develop relatively high pressures. Y

A further object of the invention is to provide a rivet'er wherein the intensifying means and i6 ram means are retracted atrelatively high speed compared to the' advancement thereof toward a work piece.

Another object of the invention is to provide liquid distributing passages within the riveter housing resulting in a more compact apparatus and reduction in the number of external high pressure conduits with less liability of leakage and damage by bursting of thepipes.

Otherobjects and advantages will become apparent during the course of the following description.

Intheaccompanying drawings vforming a p art of the description and wherein like numerals are employed to designate like parts throughout theseveral views,

Fig. l is a broken elevational view of a hydraulicl riveter and the adjuncts to suspend the rlveter and to supply hydraulic pressure thereto,

Fig. 2 is a sectional view partly in elevation taken along the line 2-2 of Fig. 4,

Fig. 3 is a sectional view taken along the line 3 3 of Fig. 2,

Fig. 4 is a sectional view taken along the line iill of Fig. 2,*and

Fig. 5 is a sectional view taken along the lines eof Fig. 2.

The portable hydraulic riveter herein disclosed comprises a housing I6 provided with a longitudinally extending iiuid cylinder II divided by 45 an annular block I2 to form' a. pressure cylinder i3 and a ram cylinder I4, the latter having a reduced end i5 embraced by an arm I 6 of a riveting yoke il which is rigidly secured to the housing i@ by means of -a nut I8 threaded on to the .an reduced end I5 of the ram cylinder I4 to draw the riveting yoke Il against the shoulder I9 of the housing. The other arm 2li of the yoke I1 is provided with a die 2i faced to accommodate a rivet not shown. l

55 Rcciprocally mounted in the' ram cylinder i4 is a ram construction 25 having a ram piston 28 and a ram 21 of ysmaller diameter which extends through the reduced endl I5 and is provided at its free end with a die 28 for cooperation with the riveting die 2l to accommodate a rivet there- 5 between. The piston 25 is provided with a seal- Y ing ring 30 and the ram 2l with sealing rings 3| to prevent passage of liquid from one side to the other thereof. Additional sealing means are disposed at the upper end of the ram piston 25 and 10 comprise an annular L-shaped yieldable packing 43 heid in positionby a nut 32 threaded on theA piston 26. The packinghas its free end 33 so disposed as to be forced vby liquid into sealing engagementI with the inner surface of the ramll cylinder I4. A ram retractingchamber 34 is. provided between the ram 2`l and the ram cylinder I4 and communicates with a source of fluid in a manner hereinafter described to retract the ram device, 25. 20

The pressure cylinder I3 isclosed by a cap 35 secured to the-housing III by a nut`36 andhas a transverse passage 39 and a central port 31 communicating with a flexible conduit 38 leading to a source of iiuid pressure. The opposite ends 25 v of the transverse passage 39 communicate through ports 40 and 4I with a pretsure chamber 42 between the cap 35 and an intensifying device 45 in ythe pressure cylinder I3. Disposed in the transverse passage 39 is a ball check valve 45 3o limited in movement in one direction -by a pin 41 and engageable with a valve seat 48 to interrupt ilow of fluid through the port 40 and thus to the pressure chamber 42.

The pressure intensifying device 45 comprises `35 l an intensifying piston fitted in the cylinder I3 and an intensifying ram 5I of smaller diameter which is slidably received in a bore 52 in the annular block I2. Sealing means are disposed at the upper end of the piston 50 and include an 40 annular L-shaped yieldable packing 55 retained by a nut 56 threaded on the piston 50 and has its free end 51 so arranged as to be forced by liquid in the chamber 42 into sealing engagement with the cylinder I3. In the intensifying piston 50 is 45 a recess 53 for the purpose of increasing the volume of the pressure chamber 42 and for reducing the weight of the piston 50. The intensifying ram 5I forms with lthe cylinder I3 an annular retracting chamber 60 which communicates with a source of fluid pressure to retract theintensifying devicev d5. f

An intensifying chamber 62 is formed between the intensifying ram 5i, the annular block I2 and 55' retracting chamber -60 and to the transverse ports 65 leading to an annular recess 66 exposed to' ports 61 disposed in the wall of the housing l0, which ports lead to a pair, of spaced passages 69 formed in the wall of the housing and extending to ports 69 leading to the ram retracting :lluidl chamber 34. The annular recess 66 also communicates with a source of fluid pressure by means of the port 1| accomodating o ne end of a flexible conduit 10 connected to the fluid pressure source, whereby fluid under `pressure is supplied to the intensifying ram retracting chamber 60 and the riveting ramretracting chamber 34. The distributing block I2 is provided with another annular recess 15 which communicates with ports 16 exposed to the intensifying chamber 62, and also communicates with a pair of ports 11 terminating in a pair of passages19 in the wall of the housingr |0 which communicate with a recess 19 in the vcap 35 at the end of the transverse passage 39 which in turn is connected to the source of fluid pressure. through the conduit 39. vThis-recess 19 is larger than 4port 4| whereby fluid first passes to chamber 62 and builds up pressure before a sumcient pressure builds up in chamber 42 to cause the ram 5| to move sumciently to close ports 16.

The riveter is suspended over pulleys 90 by means of a cable 9| and a counterweight 92 wherebyl the riveter'may. be easily manipulated into any desired position by means of the handle 93.' Disposed in the handle 93 is a conventional electric switch not shown, operated by the switch.

button 94 connected by an electric-conductor 90 to a solenoid 95 which operates a valve 96 to control the flow of liquid subjected to pressure by a pump 91. Y

The control valve 96 comprises a housing 95 provided -with a longitudinally extending bore 96 communicating with a by-pass 91 and with a port ,99connected to the flexible conduit 10, a port 99 connected to the exible conduit 39, a port |00' connected to a conduit |0| -leading to lthe pump l91 and a port |02 connected to a conduit |03` leading to a reservoir |04 connected by means of ra conduit |05 tothe pump 91. The flow of fluid through these ports is controlled by a valve |06 disposed in the bore -96 and is connected to a core |01 which is normally urged to the release position shown in Fig. l by a spring |09 in the valve housing 95.

When the hydraulic press is idle, the switch button 94 is in of! position and the valve 06 is in the position shown in Fig. l, whereby the pump 91 delivers fluid under pressure through the conduit |0|, bore 96, port 99 and flexible conduit 10 to the annular recess 66 in the distributing block |2, from which it is distributed to the passages 69 and ports 69 into the chamber 34 to support the ram means 25 in retracted posiv expeis the core |01 to move the valve |06 to he right as viewed'in Fig. l, whereby the pump 91 elivers fluid under pressure through the conduit |0|, bore 96, port 99 and flexible conduit 39 into the transverse passage 39 from which liquid passes through the passages 19, ports 11, annular recess and bores 16 into the intensifying chamber 62. The liquid entering the intensifying chamber 62 protracts the'ram means 25 and as thisv happens the volume of the intensifying chamber 62 is increased. After the ram means is protracted and meets resistance of a rivet, pressure building up in passage 39 is directed 'through the smaller port 4| into thepressure chamber 42tand moves the intensifying ram 5| into theI bore 52 of the distributing block I2 `to close the lateral ports 16, thereby preventing the escape and entrance of fluid in the intensifying chamber 62. Upon continued protraction of the intensifying ram 5| the latter exerts pressure upon the liquid confined in the intensifying chamber 62 and causes the ram 21 to exert high pressure upon the rivet placed between the rivet dies 29 and 2|.l As the intensifying ram 5| and yriveting ram 21 are advanced the pressure in the chambers 60 and 34 is relieved through the annular recess 66, flexible conduit 10, port 99, bypass 91, port |021, and conduit |03 to the reservoir |04. j t

It will be understood that the. final pressure transmitted to the riveting ram 2,1 is'extremely high compared to the initial pressure. This is due to the fact that prior to `closing the ports 16 the liquid iny the intensifying chamber 62 is subjected onlyto pump pressure, but upon closure of the ports 16 by the intensifying ram 5|, the pressure developed in the intensifying chamber 62 will be greatly lincreasedbecause the effective areaof the intensifying piston 50 is far greater than the area of the intensifying raml 5| in the chamber 62, thus causing the riveting ram 21 to impart pressures to the work' which are considerably higher than that developed by the Dump.

When the Vram 21 meets resistance of the work, pressure builds up in chamber v62 and also in 42 moving intensifying piston 5| downwardly until the port 16 is cut om The speed of the ram 21 will now slow down because less fluid is displaced by the intensifying ram 5| in chamber 62 and .enters chamberf 42, for a definite movement of the intensifying piston 50. The pressure in chamber 42 now being high and in chamber 62 still higher due to the differentialfareas of pistons 50 and 5|, the speed of the ram 21- is reduced while pressure thereon is intensified.

In order to retract the riveting ram 21y the,

under pressure through conduit |0|, port 99 and the flexible conduit 10 into the annularrecess'y 66 from which it is distributed through the ports 61, passages 69 and ports 69 to the chamber 34 to thus move the ram piston 26 upwardly. At the same time pressure builds upin the annular recess 66, the ports 64 and chamber 60, to retract the intensifying piston 50. Upon retraction of the intensifyingmeans and riveting means the pressure in the intensifying chamber 62 is relieved through the passages 19', transverse bore 39 and the flexible conduit 39 to the reservoir |04 and the pressure in the pressure chamber 42 is relieved through both f the ports 40 and 4|,

and the passage 39 and conduit 39. The speed 75 of retraction of the intensifying means and riveting means will be 'greater than the speed of advancement since both of the ports 40 and Il are open during retraction and chambers 34 and SB are of less volume than chambers 42 and 82.

It will be understood that various changes in the construction and arrangement of parts may be resorted to without departing from the scope of the appended claims.

We claim:

i. In a iiuid cylinder, ram means having a ram piston in said cylinder, and a ram, a retracting uid chamber below said piston communicable with a source of fluid for retraction of said ram means, intensifying means having an intensifying piston in said cylinder and an intensifying ram, of less area than said ram piston and intensifying piston and located above the ram piston a fluid retracting chamber below the intensifying piston communicable with said source of fluid for retraction of said intensifying'means, ported means defining an intensifying fluid chamber between said intensifying ram and said ram piston and communicable with said source of fluid to advance said ram means, a fluid pressure chamber above the intensifying piston communicable with said source of fluid, to advance said intensifying' ram into said intensifying-fluid chamber to interrupt communication of the latter with said source of fluid pressure and confine the uid therein to exert pressure upon the'iuid within said intensifying chamber to advance .said ram means, means for delivering fluid into said pressure and intensifying chambers to advance said ram means and intensifying means, means for delivering iiuid to said retracting fluid chambers to retract said ram means and said intensifying means, said retracting chambers being of less capacity than the intensifying and pressure chambers, means including a check valve to allow a 1 ymore rapid ow from said pressure chamber upon retraction of said intensifying means than upon the advancement of said intensifying means', and valve control means for directing the ow of iiuid from said pressure source to effect advance and retraction of said ram means and intensifying means.

2. In a iiuld cylinder, ram means in said cylinder, intensifying means of restricted area in said cylinder and spaced from said ram 'means to dene an intensifying uid chamber, a iluid pressure protracting chamber adjacent said intensiu fying means communicating with a source of fluid pressure to advance said intensifying means and said ram means, a fluid retracting chamber for retraction of said -intensifying means, and means including a restricted passageway communicating with said pressure protracting chamber, a port communicating with said chamber and a check valve at said port to allow more rapid flow of iiuid from said pressure protracting chamber upon retraction of said intensifying smaller than its intensifying piston and the ram piston, a second retracting chamber, means defining an intensifying fluid chamber between said intensifying ram and said ram piston, said means having a fluid chamber port exposed to chamber, the wan of said cylinder having a passage for connecting said fluidchamber port and said first retracting chamber toa source of fluid pressure for retraction of said ram means and said intensifying means, said wall of said cylinder having a second passage for connecting lsaid intensifying chamber port with a sourceof -fluid pressure to 'advance said ram means, and a' Ipressure chamber adjacent said intensifying piston communicating withv said source of fluid Apressure for advancing said intensifying means.

4. In a fluid cylinder, ram means having a ram `piston in said cylinder and a rain, a rst retracting chamber, intensifying means having an intensifying piston and an intensifying ram, said intensifying ram being smaller lin area than said ram piston and said intensifying Piston, a second retracting chamber, means dening an intensifying fluid chamber between said intensifying ram and said r piston, 4said means having a fluid chamber port exposed to said second retracting chamber and having an intensifying port. exposed to said intensifying chamber, the wall of said cylinder having a passage for connecting said fluid chamber port and said first retracting chamber to a source of uid pressure for retraction of said ram means and said intensifying means, the wall of said cylinder having a second passagefor connecting said intensifying chamber port with a source of fluid pressure 'to advance said ram means, a pressure chamber above said `intensifying piston communicating with said source of iiuid pressure for advancing said intensifying means, and means in the wall of said l duid cylinder communicating with said pressure chamber and including a check valve to allow more rapid flow of fluid from said pressure chamberupon retraction of said intensifying means than'upon advancement of said intensi-` fying means.

5. In a fluid cylinder, a dividing block therein dividing the cylinder in a pair of compartments and having a bore smaller than said cylinder'and ports communicating' with the compartments,

said block having a control port communicating with ,said bore, a ram piston mounted in the lower compartment and defining a retraction chamber beneath the same and a protraction chamber above the same communicating Vwith said bore of the block to provide an intensifying" chamber, an intensifying piston in the upper compartment dividing the same into a lower retraction chamber and an upper protraction chamber and having a reduced ram operating in said bore' of said block and adaptedto cut off communication of said control port with said bore during downstroke -of the intensifying ram, the wall of said cylinder having a passage communicating with said port, a cap for the cylinder having a control chamber connected with a source of pressure and communicating at one end with said passage in the cylinder wall to convey pressure to the intensifying chamber, said cap having a port of smaller area than said passage connecting the cap chamber to the protracting chamber above the intensifying piston to convey fluid under pressure thereto after pressure has been initiated in said intensifying chamber, and a valve controlled passage from said cap chamber to said protracting chamber normally closed by 4 intensifying piston upon creation of predominatingpressure therein. y y

6. In a fluid cylinder, a member therein dividing .the cylinder into upper and lower compartments having a ported reduced axial bore, a rst piston in said lower compartment forming 'a retracting chamber therebeneath, a second piston in the upper compartment having an intensifying ram of smaller diameter than either of said pistons operating in said reduced bore', a retracting chamber between the second piston and said dividing member, a protraction chamber a'bove said second piston, and a conduit between said protracting chamber and said ported reduced bore to supply -the latter with iluid until cut oi! by protraction of said intensifying ram. I

'7. In a fluid cylinde'rya member therein dividing the cylinder into upper and lower compartments having a ported reduced axial bore, a rst piston in said lower compartment forming a retracting chamber therebeneath, a second piston in the upper compartment having an intensifying ram of smaller diameter than either of said pistons operating in saidreduced bore, a retracting chamber between said second piston and said dividing member, a protraction chamber above said second piston, and a conduit between said protracting chamber, said ported reduced bore to supply the latter with fluid until cut of! by protraction of said intensifying ram, and said protracting chamber having means to cause a more rapid ilow from thespace above the second piston than toward said space.

GEORGE H. xEssLEa WILLIAM MEIER.. 

